code: def test_ObservationFeatures(self) -> None:
      t = np.datetime64("now")
      attrs = {
          "parameters": {"x": 0, "y": "a"},
          "trial_index": 2,
          "start_time": t,
          "end_time": t,
          "random_split": 1,
      }
      # pyre-fixme[6]: For 1st param expected `Dict[str, Union[None, bool, float,
      #  int, str]]` but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Dict[str, typing.Any]]`
      #  but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[int64]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Timestamp]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      obsf = ObservationFeatures(**attrs)
      for k, v in attrs.items():
          self.assertEqual(getattr(obsf, k), v)
      printstr = "ObservationFeatures(parameters={'x': 0, 'y': 'a'}, "
      printstr += "trial_index=2, "
      printstr += "start_time={t}, end_time={t}, ".format(t=t)
      printstr += "random_split=1)"
      self.assertEqual(repr(obsf), printstr)
      # pyre-fixme[6]: For 1st param expected `Dict[str, Union[None, bool, float,
      #  int, str]]` but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Dict[str, typing.Any]]`
      #  but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[int64]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Timestamp]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      obsf2 = ObservationFeatures(**attrs)
      self.assertEqual(hash(obsf), hash(obsf2))
      a = {obsf, obsf2}
      self.assertEqual(len(a), 1)
      self.assertEqual(obsf, obsf2)
      attrs.pop("trial_index")
      # pyre-fixme[6]: For 1st param expected `Dict[str, Union[None, bool, float,
      #  int, str]]` but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Dict[str, typing.Any]]`
      #  but got `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[int64]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      # pyre-fixme[6]: For 1st param expected `Optional[Timestamp]` but got
      #  `Union[Dict[str, Union[int, str]], int, datetime64]`.
      obsf3 = ObservationFeatures(**attrs)
      self.assertNotEqual(obsf, obsf3)
      self.assertFalse(obsf == 1)
  
imports: import json
  from unittest.mock import Mock, PropertyMock
  import numpy
  import pandas
  from ax.core.arm import Arm
  from ax.core.base_trial import TrialStatus
  from ax.core.batch_trial import BatchTrial
  from ax.core.data import Data
  from ax.core.generator_run import GeneratorRun
  from ax.core.map_data import MapData, MapKeyInfo
  from ax.core.observation import Observation, ObservationData, ObservationFeatures, observations_from_data, observations_from_map_data, recombine_observations, separate_observations
  from ax.core.trial import Trial
  from ax.utils.common.testutils import TestCase
label_desc: Use image node_id 1 for calling the ObservationsTest obj's underlying member method code with example usage: obj.test_ObservationFeatures() without return types